Identification of size and concentration of submicron particles on the basis of rayleigh scattering model

A method of identification of maximum size and concentration of submicron aerosol particles based on measurement of intensity attenuation of a parallel beam of probe optical radiation is described. Offered method makes it possible to determine both particle concentration and maximum particle size with controlled accuracy for aerosol media without any initial information about particle size distribution

Features of structural-phase state of Pd-Ag nanoparticles supported on silica gel

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Synthesis, Morphology, and Optical Properties of Au/CdS Hybrid Nanocomposites Stabilized by Branched Polymer Matrices

Metal/semiconductor (Au/CdS) nanocomposites were synthesized in the solution of branched D-g-PAA polymer. TEM and DLS of Au/CdS/D-g-PAA nanocomposites revealed complicated nanocomposite structure consisting of the Au nanoparticles (NPs) of 6 nm in size surrounded by small CdS NPs with size of 3 nm. These nanocomposites formed the aggregates-clusters with average size of 50–800 nm. Absorption spectra of Au/CdS nanocomposites consist of the bands of excitons in CdS NPs and surface plasmons in Au ones. The surface plasmon band of gold NPs is red shifted and broadened in Au/CdS/D-g-PAA nanocomposites comparing to the one of Au NPs in Au/D-g-PAA proving the fact of close location of CdS and Au NPs in the synthesized Au/CdS/D-g-PAA nanocomposites. The PL spectra of Au/CdS nanocomposites originate from the radiative transitions in excitons in CdS NPs. The 4-fold increase of intensity of free exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA that is due to PL enhancement by local field of surface plasmons of Au NPs. Also, the 12-fold decrease of intensity of localized exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA. Most probably, it is due to passivation of the surface of CdS NPs carried out by the Au ones

Morphology of ceramic particles produced by plasma-chemical synthesis

Thermal and diffusion processes in the droplet weakly concentrated metal salt solution during its heating in the plasma chemical reactor, in order to synthesize metal oxide powders are considered. Numerical study is based on previously proposed physical-mathematical model. The results of numerical calculations are analyzed to assess the possible influence of the operation parameters of the reactor and the characteristics of the initial solution (precursor) on the morphology of the particles formed

Обґрунтування показника проектної врожайності на осушуваних землях як основи оцінювання їхньої ринкової вартості

Scientific and methodical approaches to justification of design productivity of crops on the reclaimed lands with the regulated water mode on the basis of application of a complex of expected and imitating models are considered. It’s offered to estimate the market value of farmlands taking into account an indicator of the calculating design productivity displaying her achievement in the conditions of reclamation objects with bilateral regulation of the water mode. Розглянуто науково-методичні підходи до обґрунтування проектної врожайності сільськогосподарських культур на меліорованих землях з регульованим водним режимом на основі застосування комплексу прогнозно-імітаційних моделей. Запропоновано оцінювати ринкову вартість осушуваних земель на основі показника розрахункової проектної врожайності, яка відображає її досягнення в умовах меліоративних об’єктів з двостороннім регулюванням водного режиму

Effects of combination antihypertensive therapy on intracardiac hemodynamics and blood vessels in patients with coronary heart disease, post-infarction cardiosclerosis and arterial hypertension

The aim of the work is to assess the effectiveness of prescribing a fixed-dose combination of amlodipine with the ACE inhibitor lisinopril or with the angiotensin 2 receptor blocker valsartan in patients with coronary artery disease, acute coronary syndrome with hypertensive disease regarding the impact on the structural and functional parameters of the heart and extracranial branches of the brachiocephalic arteries. Materials and methods. General clinical examination of 108 patients with postinfarction cardiosclerosis and hypertension was done within 12 months. The patients were allocated to two groups. Patients in the first group (n = 50) were assigned a fixed-dose combination of lisinopril and amlodipine (20 mg and 5 mg, respectively), and patients in the second group (n = 58) received a fixed-dose combination of valsartan with amlodipine (160 mg and 5 mg, respectively). The patients were monitored for 12 months, including general clinical examinations, measurements of office blood pressure (BP), 24-hour BP monitoring, echo-dopplerographic examination of the heart and brachiocephalic arteries, determination of the composite endpoint. Statistical analysis of the obtained data was performed using Microsoft Excel, IBM SPSS Statistics v.23. Results. A significant difference in echocardiographic data has been proved (p 0.05) have been found in the first group. When analyzing the indicators of diastolic function in the second group, a highly significant (p < 0.05) decrease in E/A, E/E’, IO of the LA has been revealed; data analysis on the morphofunctional state indicators of the extracranial arteries has shown a CIM reduction and a decrease in PSV and RI. Conclusions. Prescriptions of the fixed-dose combination of amlodipine with the ACE inhibitor lisinopril was more effective in terms of the LV measurements (p < 0.05) and LV diastolic function as evidenced by decreased E/A, E/E’ and IO of the LA (p < 0.05) as compared to the data in the group of amlodipine with the angiotensin 2 receptor blocker valsartan. Both fixed-dose combinations were effective in reducing the CIM thickness, decreasing PSV and RI when analyzing the morphofunctional state findings of the extracranial arteries

Shape controlled iron oxide nanoparticles: inducing branching and controlling particle crystallinity

Anisotropic nanoparticles (NPs) have garnered a great deal of attention for their applications in catalysis, magnetism and biomedicine. However, synthetic strategies to grow such NPs are still limited as their growth mechanisms are poorly understood. This work presents the synthesis of iron oxide nanoparticles (IONPs) based on the decomposition of iron(III) acetylacetonate in organic solvents to form anisotropic IONPs that are branched or multiply branched. We fully explore their growth parameters to understand the effect of varying amounts of oleylamine (OAm), as well as a nitrogen purge on particle morphology. We show here the synthetic relationship between a wide range of sizes and shapes of IONPs that are both isotropic and anisotropic. Of all the parameters, the amount of oleylamine in the reaction is the key to tune the particle size while the effect of a nitrogen gas purge during synthesis was shown to be crucial for the formation of the branched and multiply branched NPs. Two multiply branched NP systems with only a small difference in the synthetic conditions were shown to have radically different magnetic properties, such as heating in an alternating magnetic field. This was attributed to the defects found in the structure of one and not in the other. By following their development during growth, crystal defects were observed in both systems during the early stages of the reaction. However, for the multiply branched structure that became single crystalline, the aggregation of the nuclei occurred earlier in the reaction, allowing more time for growth and crystallite rearrangement to occur. These results have wide ranging implications for controlling the properties of anisotropic nanomaterials with similar structures, including their magnetic behavior